The Australian Greens say it's outrageous that other parties are shielding the federal parliament and public service from corruption investigations, by refusing to vote on the creation of a national version of ICAC.

"I am disgusted that Labor and the Abbott government have joined forces to stand in the way of a national ICAC and I think Australians will be too," said Greens Leader Christine Milne.

Ahead of the push for a vote on a national ICAC in the Senate tomorrow morning, the Australian Greens say both Labor and Tony Abbott's Liberals have failed to declare a position on the national anti-corruption legislation.

"We need to take urgent action on corruption and we can. It's never been more obvious that we need a national ICAC," Greens Leader Christine Milne said.

"What are Labor and the Coalition hiding from?